A timepiece that is constructed so that, by receiving a radio wave including time information, the time may automatically be corrected to a correct time has already been put to practical use. Also, radio waves including time information that are used for radio wave correction, such as a “long wave” radio wave, have nowadays been transmitted in a plurality of countries such as Japan, the United States, Germany, Britain, etc.
However, regarding the above-described radio waves including time information, their frequency and transmission data format are different from each other.
On the other hand, the United States of America has four districts (regions) within her country each having a time difference that being different from each other. (For example, in Los Angels, a time that is obtained by subtracting 8 hours from the reception time (UTC time) is the local time (regional time) in that district; and in New York, a time that is obtained by subtracting 5 hours from the reception time (UTC time) is the local time (regional time) in that district.) In spite of this, the radio waves including time information and that are transmitted in U.S.A, is only one radio wave including the universal time information (UTC time)therein and which is transmitted only from the State of Colorado.
For this reason, after the user has received that radio wave, it is necessary for an user to separately perform adjusting operation for a time difference between the UTC time and the local time on the radio controlled timepiece side.
Also, in the United States, daylight saving time is introduced.
Therefore, after the user has received the above-described radio wave, it is necessary for the user to additionally judge at the time when the user has received the radio wave, whether or not daylight saving time has been put into effect and further adjust the above-described time difference once again.
On the other hand, in Japan, two types of radio waves including time information and each having frequency being different from each other, are transmitted, in one region
Accordingly, in a case when an user of the timepiece moves from one country to another different country with a radio controlled timepiece that is equipped with a reception system that is able to receive a plurality of radio waves including time information each being different from each other and each being uniquely to the respective country, performing a lot of complex operations become needed.
For example, in a case when an user moves between the United States and Japan, conventionally, it is necessary for the user to perform time setting operation by judging in which time zone the user is staying now (for example, by judging whether the user is in Japan, or Los Angels, or in New York)
In addition thereto, with linking this zone setting operation, a name of a country where the reception is made and an radio wave that is to be received in that country, are selected and fixed (note that, when Japan is selected, only Japanese radio waves are received.).
In addition, in a case when the radio controlled timepiece is used in a country where daylight saving time is carried out, a setting operation for the daylight saving time becomes separately needed. (Although the daylight saving time can also be corrected by receiving the relevant radio wave, when the reception is impossible and manual setting is needed, the setting operation for daylight saving time becomes separately needed in addition to the setting operation for the time zone.)
Therefore, for example, in a case when an user has moved from Japan to the United States of America where the daylight saving time is carried out, two separate operations of performing the setting operation for a zone plus the setting operation for the daylight saving time become needed. So the user feels inconvenience in doing so.
On the other hand, in a Japanese official gazette of Japanese Patent No. 3868465, there is described a method of performing an automatic correction of the displayed time of a timepiece using a time code signal that is transmitted through an radio wave used for a radio receiver. More specifically, in order to automatically correct the time information of a movable timepiece, it is described that more than one frequencies of radio waves with which a time signal is transmitted, are previously registered with the respective zone information and in a destination area where the timepiece has been moved, an operation for correcting time is performed using the corresponding frequency that was registered in the respective destination area.
Also, in a Japanese official gazette of Japanese unexamined Patent publication (KOKAI) No. Hei-5-19071, there is described a timepiece that displays a universal time. In more detail, there is described a timepiece that is constructed so that a universal time can be calculated from local standard time information and a time difference information between that time information and that universal time and there may be displayed this calculated time.
However, regarding the above-described prior arts, any of them doesn't disclose a construction which, in a globalized radio controlled timepiece, enables the user simply to perform the time difference adjustment that includes a time difference based on the daylight saving time being executed when the user moves.
On the other hand, in a radio controlled timepiece, as described above, that receives a standard radio wave including time information with a minimized antenna and automatically performs time correction, although it is possible to correctly display the time information included in the standard radio wave that has been received, such function has also aspects of inconvenience as well. For example, even when, in order for the user of a radio controlled timepiece to obtain some advanced margin to his scheduled time, the user wishes to try to display time with giving some prescribed advanced time from the standard time that received, this was followed by the following inconvenience. Namely, in a radio controlled timepiece, since when a standard radio wave has been received, the time of the timepiece is automatically corrected to the standard time that has been received, the user has a difficulty of displaying time with advancing with the prescribed margin of time relatively to the standard time or delaying in the same way.
To solve the above-described points of problem, as illustrated in, for example, Japanese official gazette of Japanese un-examined Patent Publication (KOKAI) No. 2001-13280 or Japanese official gazette of Japanese un-examined Patent publication (KOKAI) No. Hei-4-83196, a timepiece has been proposed which comprises a time information reception means that receives a radio wave including time information, an input means that inputs a time difference information showing a difference between time information that has been received and time information that is displayed, with one minute as an units a storage means that stores the time difference information, and a time correction means that corrects the displayed time information according to the time difference information.
According to the timepiece or information apparatus that is disclosed in each of the above-described known techniques, it is possible to advance or delay the time that is being displayed relatively to the time information that has been received, along the user's intention.
Therefore, not only does it have a high reliability on the display of time but it is also possible to arbitrarily display the time that the user wants to display. Therefore, the user can use it as a timepiece that is easy to use.
However, in the above-described timepiece or information apparatus, since the setting of the time difference relative to the time information is performed with an unit of one minute, in a case when the inputting operation for the time difference information is carried out with an unit of one minute, it is certainly possible to input this information with a relatively simpler manner. However, in a case when the time difference information exceeds an hour, the number of times of the inputting operations becomes increased, resulting in the operation becoming very troublesome. Especially, in a case when a person who uses the timepiece has moved, within an area where a standard radio wave is used, from one country or region to another country or region each having the respective time difference being different from each other, there arises the necessity for correcting the time to the standard time as used in that country or region to which the user moved. However, since the minimum unit of time in which a time difference changes is usually one hour, when the time difference information is input, it is necessary to input the time difference information at least for exceeding one hour.
Therefore, an inputting operation for that information with an unit of one minute, makes this inputting operation troublesome, resulting in causing operating efficiency of the timepiece to have significant problem.
Also, in a case when it is unable to receive a standard radio wave including time information, it is necessary to manually perform the time correction. However, in the timepiece proposed as described above, because no consideration is taken to the time correction in a case when it is unable to receive a standard radio wave including time information, if, for example, no reception of a relevant standard radio wave could be made by any reason, it becomes possible that the timepiece will be unable to perform a function as a timepiece. This shows that this timepiece includes a problem over its basic function.
An object of the invention is to provide a radio controlled timepiece that eliminates the above-described drawbacks in the past radio controlled timepiece and that, in a case when the user who uses that radio controlled timepiece moves between countries or regions each having the respective time difference being different from each other, eliminates the necessity of the user separately performing two different operations for correcting the time difference existing between two of those countries of regions and for correcting the time difference based on the daylight saving time as executed, and thereby enables to complete all necessary the time-difference correction or adjustment with one radio wave operation.
Another object of the invention is to provide a radio controlled timepiece that, in a case when the setting operation for the time difference is performed in connection with the user's moving from one country or region to another where the time difference is different from each other, enables for the user to perform the setting operation easily and further, even in a case when the user is unable to receive a standard radio wave, enables him to simply perform correction of the time information of his timepiece with his manual operation so as to provide a radio controlled timepiece having high operating efficiency and excellent reliability.